diff --git a/admin/translators.php b/admin/translators.php
index 9cf4dd8..a11b80e 100644
--- a/admin/translators.php
+++ b/admin/translators.php
@@ -43,7 +43,7 @@
 $languages = mlang_tools::list_languages(false);
 
 if (!isset($languages[$langcode])) {
-    print_error('error_unknown_language', 'local_amos', '', $langcode);
+    throw new \moodle_exception('error_unknown_language', 'local_amos', '', $langcode);
 }
 
 if ($action === 'add') {
@@ -54,7 +54,7 @@
         $actionname = get_string('creditsaddcontributor', 'local_amos');
         $selector = new local_amos_contributor_selector('user', []);
     } else {
-        print_error('error_unknown_status', 'local_amos', '', $status);
+        throw new \moodle_exception('error_unknown_status', 'local_amos', '', $status);
     }
 
 } else if ($action === 'del') {
@@ -64,7 +64,7 @@
     } else if ($status == AMOS_USER_CONTRIBUTOR) {
         $actionname = get_string('creditsdelcontributor', 'local_amos');
     } else {
-        print_error('error_unknown_status', 'local_amos', '', $status);
+        throw new \moodle_exception('error_unknown_status', 'local_amos', '', $status);
     }
 }
 
@@ -160,5 +160,5 @@
     echo $OUTPUT->footer();
 
 } else {
-    print_error('error_unknown_action', 'local_amos');
+    throw new \moodle_exception('error_unknown_action', 'local_amos');
 }
diff --git a/contrib.php b/contrib.php
index e1263ac..d6fcd8f 100644
--- a/contrib.php
+++ b/contrib.php
@@ -72,7 +72,7 @@
 
     if ($maintainerof !== 'all') {
         if (!in_array($contribution->lang, $maintainerof)) {
-            print_error('contributionaccessdenied', 'local_amos');
+            throw new \moodle_exception('contributionaccessdenied', 'local_amos');
         }
     }
 
@@ -143,7 +143,7 @@
 
     if ($maintainerof !== 'all') {
         if (!in_array($contribution->lang, $maintainerof)) {
-            print_error('contributionaccessdenied', 'local_amos');
+            throw new \moodle_exception('contributionaccessdenied', 'local_amos');
         }
     }
 
@@ -190,7 +190,7 @@
 
     if ($maintainerof !== 'all') {
         if (!in_array($contribution->lang, $maintainerof)) {
-            print_error('contributionaccessdenied', 'local_amos');
+            throw new \moodle_exception('contributionaccessdenied', 'local_amos');
         }
     }
 
@@ -241,7 +241,7 @@
 
     if ($maintainerof !== 'all') {
         if (!in_array($contribution->lang, $maintainerof)) {
-            print_error('contributionaccessdenied', 'local_amos');
+            throw new \moodle_exception('contributionaccessdenied', 'local_amos');
         }
     }
 
@@ -285,7 +285,7 @@
     $listlanguages = mlang_tools::list_languages();
 
     if (empty($listlanguages[$newlang])) {
-        print_error('err_invalid_target_language', 'local_amos', new moodle_url($PAGE->url, ['id' => $contriborig->id]),
+        throw new \moodle_exception('err_invalid_target_language', 'local_amos', new moodle_url($PAGE->url, ['id' => $contriborig->id]),
             null, $newlang);
     }
 
diff --git a/stash.php b/stash.php
index 7a3a90b..cb03edb 100644
--- a/stash.php
+++ b/stash.php
@@ -59,7 +59,7 @@
     require_capability('local/amos:stage', context_system::instance());
     $stash = mlang_stash::instance_from_id($apply);
     if ($stash->ownerid != $USER->id) {
-        print_error('stashaccessdenied', 'local_amos');
+        throw new \moodle_exception('stashaccessdenied', 'local_amos');
         die();
     }
     $stage = mlang_persistent_stage::instance_for_user($USER->id, sesskey());
@@ -73,7 +73,7 @@
     require_capability('local/amos:stage', context_system::instance());
     $stash = mlang_stash::instance_from_id($pop);
     if ($stash->ownerid != $USER->id) {
-        print_error('stashaccessdenied', 'local_amos');
+        throw new \moodle_exception('stashaccessdenied', 'local_amos');
         die();
     }
     $stage = mlang_persistent_stage::instance_for_user($USER->id, sesskey());
@@ -87,7 +87,7 @@
     require_sesskey();
     $stash = mlang_stash::instance_from_id($drop);
     if ($stash->ownerid != $USER->id) {
-        print_error('stashaccessdenied', 'local_amos');
+        throw new \moodle_exception('stashaccessdenied', 'local_amos');
         die();
     }
     $confirm = optional_param('confirm', false, PARAM_BOOL);
@@ -115,7 +115,7 @@
     require_sesskey();
     $stash = mlang_stash::instance_from_id($download);
     if ($stash->ownerid != $USER->id) {
-        print_error('stashaccessdenied', 'local_amos');
+        throw new \moodle_exception('stashaccessdenied', 'local_amos');
         die();
     }
     $stash->send_zip("stash.zip");
@@ -129,7 +129,7 @@
 } else if ($submitdata = $submitform->get_data()) {
     $stash = mlang_stash::instance_from_id($submitdata->stashid);
     if ($stash->ownerid != $USER->id) {
-        print_error('stashaccessdenied', 'local_amos');
+        throw new \moodle_exception('stashaccessdenied', 'local_amos');
         die();
     }
 
@@ -231,7 +231,7 @@
     require_sesskey();
     $stash = mlang_stash::instance_from_id($submit);
     if ($stash->ownerid != $USER->id) {
-        print_error('stashaccessdenied', 'local_amos');
+        throw new \moodle_exception('stashaccessdenied', 'local_amos');
         die();
     }
     echo $output->heading_with_help(get_string('submitting', 'local_amos'), 'submitting', 'local_amos');